WATER VAPOR INTERACTION IN THE Cè_1-XU_XO₂ SYSTEM

Ceria (CeO₂) and doped ceria are considered favorite candidates in oxidation/reduction applications and processes, like hydrogen production and solid oxide fuel cells (SOFC). This is due to the ease at which cerium ions can transform from Ce(IV) to Ce(III) and vice versa. Incorporation of dopants in ceria can improve its adsorption properties and efficiency as catalytic surface. While most works of doping in ceria discuss the incorporation of trivalent ions. Recent studies showed that use of uranium increases the hydrogen production efficiency compared to the pure oxides. In this study, several techniques are used in order to study the interaction of water vapor with the Ce_1-xU_xO_2, surface including water adsorption experiments, X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The experimental results indicated that the Ce_0.75U_0.25O₂ composition presents a different oxidation behavior and a different adsorption energy of water compared to the higher U containing compositions.